Spark-plug



A. L. RIGGS.

SPARK PLUG.

RPPLICATXON man OCT. 29. 1911.

1 ,265 ,5 1 8 Patented May 7, 1918.

INVENTOR v AL}; 2378 y yam ATTORNEY ALFRED LEANDER RIGGS, OF EBENSIBURG, PENNSYLVANIA.

SPARK-PLUG.

Specification of Letters Patent.

Application filed October 29, 1917. Serial No. 198,941.

2 b all whom it may concern:

Be it known that I, ALFRED L. Rloes, a citizen of the United States, residing at Ebensburg, in the county of Cambria and State of Pennsylvania, have invented new and useful Improvcnn-uts in Spark-Plugs, of which the following is a specification.

This invention relates to spark plugs and has for its object the provision of a spark plug in which it is possible to determine at a glance whether or not current is being fed to the electrodes or being short circnited lor an ol' the usual reasons.

The present inumtiou is an improvement n applications filed October 5, 1916, Serial No. 123,923 and January :23, 1911'. Serial No. name.

The "imary object of the present inven lien is an provide a spark plug of the above class in which provision is made for thc escape of ozone formed by the ele tric spark, so as to prevent discoloration of the glass through which the spark is visible.

Another object is to provide novel means for securing the glass in position so as to provide for a slight variation in the diameter of the insulating core of the plug, in order to peiuiit of the assembling of the parts.

ther objects and advantages of the in \cnlion will be apparent when the follow ing description is read in connection with the accouipmiying drawings, in which- Figure l a perspective view of the spark plug embodying the present inveir tion;

Fig. :2 through the core;

Fig. 3 is a horizontal sectional view on the line 3-3 of Fig. 2;

Fig. 4- is a detail perspective view of a removable cap;

Fig. 5 is a similar view of the clamping band Fig. 6 is a sectional view on the line 0-4) of Fig. 3 illustrating the means for preventing the accidental turning of the se urin not and the terminal block; and

l ig. 7 is a detail perspective view of the terminal block.

Referring to the drawings in detail, like characters of reference denote correspondin parts throughout the several views. i

is a transverse sectional v.iew taken upper portion of the porcelain n the drawings, there is illustrated a spark plug 10, proyided with an insulating Patented May 7, 1918 core 11, through which extends one of the electrodes 12, the said electrode projecting beyond the surfiicc of the core.

Mounted upon the core 11 is end of which provided with extending flange 14, which opening 15 formed in the cap. ing is closed by a disk hold in position by aiust; the under edge of The cap 13 is split as acap 13, one an inwardly surrounds an This openm'dcr that it might accommodate itselfito insulating cores of slightly different diametcr. lhis cap is further provided at the cud opposite the glass 16 with an outwardly turned flange 18, which is adapted for engagement; with one end of a clamping band 1 and has formed thereon at di'an The band 19 extends around the cap iet'rically opposite points, inwardly extending engaging in .20 which are ada ited to en a c an annular groove 21 formed in tug core 11. gaging tho groove :21. I,

formed in the flange is at t the, insulat The lugs 20 in additionto enpass through recesses lia n'ietrieally opposite points, these flanges engaging ben ath the edge of the cap 1 3 at while the flange 15" migages adjacent edge the said band is secured in pos will he effectually held in position upon the (tllii Formed upon the hand 19 extending parallel portions these points, beneath the of thc hand 19, so that when ition the cap are oppositely 23, which are prov ded with alined openings LB-l, a screw -25 being passed through these engagement with which the miual block 27. which has proj openings for a nut 26, by means of band is tightly secured upon the 25 is a tereetlng therefrom a threaded stud 28 a binding nut 29 being posit ioncd upon this stud \vhiclrthe electrical conductor ring 30 is connected to the pit the outwardly extending formed with lalernllv by means of for the feed 1g. Each of portions are exl'cndlng locking flanges 3!. which arc adapted to engage one edge of the nut 20 and the bloc k "27, to hold these elements against turning.

The glass top 10 of the cap 13 is spaced from the top of the insulating core 11, so as to provide an electrode chamber 32,

which extends the electrode I mentioned and the electrode 3 the feed ring 30. One of the most important features of the invention resides in roviding ventilating means for this cham- ,ber, in order to prevent discoloration of the glass 16 byuthe ozone from the electric spark withinthis chamber. To this end the sides of the cap 13 are formed with ventilating 0 enings 34, preferably arranged around t 0 cap, the retaining ring 17 also being provided with similar openings, so as to permit ofthe escape of the ozone and to prevent discoloration of the glass.

It is believed that from the foregoing description when taken in connection wit the accompanying drawings, the construction and advantages of the invention will be apparent. The richt is reserved to make such chan es in the term and proportion thereof as will fall within the scope of the claims hereto appended.

Havin described the invention, what is claimed 1s-- 1. In a spark plug a cap removably mounted upon the insulating core, said cap being slitted to provide adjustment, a clamp for securing'the cap u on carried by said clam or engagement with said core and means ,ocated at t e open end of said cap for enga ment with the clam 2. In a spark p ug, a cap removabl y includingportions,

the core, means mounted upon the insulating core; said cap being slittsd to provide adjustment, a clamp for securing the cap u on the core, means carried by said clam or engagement with said core and means ncluding an outwardly extending flange formed on said cap for engagement with the clamp.

3. In a spark in a cap removably mounted upon'the msu' ating core said core having formed therein a c rcumlerentially arranged groove, a clam surrounding s d cap, means carried by ea (1 cap for engagement with said clampand lugs formed on said clamp for engagement with th g e in'the insulatin core.

4. The combination with a spark plug provided with a removable cap, of a clamp securing said cap u outwar y extending terminal an adjusting screw for securin said clamp in position, a terminal bloc pivotally secur between said terminal portions n on said screw, a nut for holding the screw in position and laterally extending flanges carried by the terminal portions an engageable with one edge of said block and nut.

In testimony whereof I aifix my signature.

ALFRED LEANDER mess;

on said plug, said clamp 

